The invention relates to a fixation system for bones with a sensor and telemetry system.
Fixation systems are used in osteosynthesis, wherein the connection support bridges the fracture and is connected with the bone fragments via at least one bone screw. The connection support is for example a bone plate, a marrow nail or external fixation. It is thereby advantageous if the bone screw in the connection support is blocked in a permanently angle-stable manner.
Particularly advantageous is the selectability of the screw direction before the permanently angle-stable blocking of the bone screw in the connection support. The angle-stable connection of bone screw and connection support leads to a stability increase for the entire assembly trough the special type of transfer of forces and loads. This transfer is characterized by the area-wise force distribution. Furthermore, biomechanical and clinical results indicate better healing processes.
The check of the healing processes during osteosynthesis is possible through so-called imaging procedures. Above all, this concerns X-ray examinations, magnetic resonance imaging and computer tomography. It is known that the informational value of these imaging procedures lags several weeks behind that of the actual healing process.
It is required to safely assess the ability of the healing tissue with respect to the transfer of forces in order to be able to close on the status of the healing process, to be able better conduct aftercare and to identify early on potential defective healings.
Fixation systems for bones were already combined with sensor systems earlier. Resistance strain gauges were hereby used, which were connected with cables, which were led through the skin to the outside. The problem of infections in particular caused these types of systems to only be used in exceptional cases.
For several years, sensor systems that work together with a telemetry system, which transmits the measurement values obtained from the sensor system in the body to the outside wirelessly, have been used in clinical applications The production of these systems is difficult, complicated and cost-intensive. Thus, these systems have only been used in individual cases—e.g. in the area of the spinal column or the hip joint—in order to answer questions regarding the load tolerance, the forces and after healing. Sensor and telemetry systems are connected with the fixation system through adherence.
Based on the fixed connection of fixation, sensor and telemetry system, the operator must make a decision early enough about whether the patient needs this combined system.
Only at the end of the operation, after the bone fixation is complete, is an assessment possible with respect to the future healing process. Many important factors for the healing are impacted by the operative progression.
U.S. Pat. No. 6,034,296 and WO-A-2005074821 disclose fixation systems for bones with a connection support, at least one bone screw that can be inserted into a through hole of the connection support and a sensor and telemetry system, which is arranged on a separate plate, which can be connected with the connection support.
Based on this assumption, the object of the invention is to create a fixation system for bones with a sensor and telemetry system, in which the force flow takes place via the sensor system.